Meitnerite

meitnerite

beshtauite

boussingaultite

greenlizardite

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Formula: (NH4)(UO2)(SO4)(OH).2H2O
Sulphate, uranyl mineral
Crystal System: Triclinic
Specific gravity: 3.320 calculated for the empirical formula
Hardness: 2
Streak: Very pale yellow
Colour: Slightly greenish yellow
Luminescence: Fluoresces greenish-white under 405 nm light
Solubility: At room temperature, slowly soluble in water and very rapidly soluble in dilute hydrochloric acid
RADIOACTIVE
Environments

Sedimentary environments
Hydrothermal environments

Meitnerite is a relatively new mineral, approved in 2017.

Localities

At the type locality, the Green Lizard Mine, Red Canyon Mining District, San Juan County, Utah, USA, meitnerite was discovered on a specimen collected underground. Mineralised channels are in the Shinarump member of the Chinle Formation (late Triassic, 252 to 201 million years ago). The Shinarump member consists of medium- to coarse-grained sandstone, conglomeratic sandstone beds and thick siltstone lenses.
Accumulations of wood and other plant material in the channels provided reducing environments that caused the deposition of the ore minerals, which are found as replacements of the organic material and as disseminations in the enclosing sandstone. Since the mine closed, oxidation of primary ores in the humid underground environment has produced a variety of secondary minerals, mainly sulphates, as efflorescent crusts on the surfaces of mine walls. The (NH4)+, essential to meitnerite and several other secondary phases, presumably derives from the organic matter.
Meitnerite is a very rare mineral, found on only one small specimen in association with beshtauite and gypsum on quartz. Besides meitnerite and beshtauite, other secondary NH4-bearing phases found in the Green Lizard mine include ammoniozippeite, boussingaultite and greenlizardite. Other secondary minerals found in the mine assemblage include arsenuranospathite, bobcookite, calcite, dickite, fermiite, johannite, magnesioleydetite, metakahlerite, nováčekite-II, natrozippeite, oppenheimerite, plásilite, rozenite, shumwayite, strassmannite, sulphur, wetherillite and other potentially new uranyl sulphate minerals.
Meitnerite occurs as intergrowths of tabular crystals up to about 80 mm across and 30 mm thick (EJM 30.5.999-1006).

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